Tuner antenna control



Aug. l0, 1965 M. B. lRoLER TUNER ANTENNA CONTROL 5 Sheets-Sheet 1 Filed May 3, 1963 INVENTOR Mai/'55 ,590.: E@

BY W Aug. 10, 1965 M. B. IROLER TUNER ANTENNA CONTROL 3 Sheets-Sheet 2 Filed May 3, 1963 INVENTOR Mau/WCE 5. /RoL ER BY Mug )l 5MM ATTORNEYS .for VHF operation.

United States Patent 3,200,314 TUNER ANTENNA CONTROL Maurice Benton Iroler, Fancy Gap, Va. Filed May 3, 1963, Ser. No. 277,837 11 Claims. (Cl. 318-33) `This application is a continuation-in-part of my application Serial No. 81,664, filed January 3, 1961, under the same title, now abandoned, and contains all the subject matter therein and more. The invention herein, as therein, relates to the automatic control of the azimuthal or rotational position of a receivers antenna in accordance with the station or channel selected.

Though this invention is described with particular relation to a television receiver, it is also applicable to other types of receivers which require their respective antennas to be positioned or directed in different directions to best receive the signals transmitted from respective stations.

In the past, it has been necessary for home television receiver operators, for example, to utilize a double throw switch for remotely controlling the rotational movement of a roof antenna for their television receiver, after selecting a given station torbe viewed. This, of course is bothersome, inconvenient and not always is the antenna positioned accurately in that manner.

It is the principal object of this invention to overcome the disadvantages of manual control of a receivers remotely rotatable antenna by automatic positioning of the antenna in a rotational position responding to the station selected.

Another object of this invention, in conjunction with the foregoing object, is the provision of automatic antenna positioning equipment which does not require a selsyn or other type of expensive follow-11p systems but yet the antenna rotator and control motor according to this invention are resynchronized now and then and in-between times keep suciently synchronized to position an antenna tolerably accurate, for example within 110 or so.

The specific apparatus for accomplishing this includes a unit which is integral with or connectable to the shaft of a tuner in the receiver. As is well known in television receiver art, an external knob is employed to manually change the turner circuits and select any one of a plurality of stations or channels, numbered 2 through 13 Rotation of the selection knob is such that the knob and the tuner shaft to which it is connected are detented at each one of the different channel indicators. The unit of this invention which may be attached to such a tuner shaft has a multiposition switch the arm of which rotates with the tuner shaft. The number of positions of this switch is at least equal to the number of usable channels on the TV set, and each position of the switch is electrically connected to a different channel Contact bar which co-extends insulatively relative to each of the other contact bars. These bars are posi` tioned around a block or the like which is movable as by an auger lengthwise of each of the bars simultaneously. Attached to the block at respective positions are a plurality of spring contact means for making respective electrical contact with the channel bars and to a further common bar. Positioned on each of the bars is a respective circuit breaker or disconnet means which is adjustable in position lengthwise of the bar for breaking electrical contact between the particular bar and the spring contact on the block. All of the spring contacts are connected together and thereby to the common bar. A reversible motor is employed to rotate the auger and move the block in opposite directions along the bars, and the motor is energized as soon as the station selecting knob is rotated to a particular channel. The block therefore begins to at least approximately cor- 3,2%,314- Patented Aug. 19, 1955 move and as soon as it encounters the circuit breaker associated with the selected channel, the motor circuit is broken and the block stops its movement. The circuit which operates the reversible motor that moves the block longitudinally of the bars, is also connected to the remote antenna motor to reversibly rotate the antenna. Therefore the antenna is rotated only the angular distance corresponding to the longitudinal movement of the block along the contact bars. There is also provision for reversing the direction of block movement, and consequently of the antenna motor direction, when the block approaches either end of its travel.

It is therefore another object of this invention to provide apparatus which has the features described above.

Other objects and advantages of this invention will become apparent to those of ordinary skill in the art after reading the appended claims and the following detailed description of the invention in conjunction with the drawings, in which:

FIGURE 1 is a diagrammatic representation of the application of this invention to a television receiver and its remote rotatable antenna.

FIGURE 2 is a partial diagrammatic representation indicating a variation in the invention,

FIGURE 3 is a schematic and diagrammatic illustration, partly in structural cross section, showing the details of the automatic control apparatus of this invention,

FIGURE 3A is a complete electrical schematic diagram corresponding to FIGURE 3.

FIGURE 4 is a cross sectional view taken approximately along the line 4 4 of FIGURE 3, and

FIGURE 5 is a view taken approximately along the line 5 5 of FIGURE 3.

In FIGURE l a conventional television receiver is connected by a common type transmission line 12 to a remote antenna 14 positioned, for example, atop a roof 16 of the home containing the television receiver. The antenna may be held upstanding on a conventional mast 18 and may be angularly rotated in any azimuthal direction by a conventional reversible rotator or motor 20, which has the usual down gearing and a stop (not shown) to prevent rotation substantially beyond 360 so that its leads cannot become twisted around the mast. As previously indicated, normally a television receiver operator must irst turn the station or channel selection knob 22 so as to make the proper frequency selection by tuner 24 in the receiver, and then he has had to operate a single pole double pole switch (not shown) for purposes of sending a forward or reverse signal to motor to rotate antenna 14 until the picture on the screen of the television screen appeared the best. Sometimes other factors enter in and such manual control of the rotational position of antenna 14 leaves much to be desired in the Way of its accurate resulting direction to Ward the transmitting station selected.

In accordance with this invention, however, an automatic ycontroller 26 is interposed between the antenna motor Ztl and the receiver tuner 24, to cause automatic positioning of the antenna in accordance with the station or channel manually selected by knob 22. This automatic controller may be coupled to the tuner shaft 28 by a tlexible cable 30 whereby the controller 26 may be disposed externally of the television receiver. On the other hand, the input shaft 32 of the controller may be an integral extension of, or directly rigidly connected to, tuner shaft 28 as shown in FIGURE 2, whereby the controller 26 may be positioned within the television receiver cabinet. Either embodiment is equally satisfactory from the operational standpoint, and the interconnection between the tuner and controller, as well as the location of the latter, may be as desired.

The controller 26 of FTGURES Vl and 2 is shown in detail in FTGURE 3. vTherein, a plastic housing 3d for the controller sits on a base 35. The housing may be madeof plastic parts molded or otherwise formed to the shape desired. In any event, the input shaft 32, which vmay be coupled as previously indicated by a flexible shaft 3d to a televisionl tuner,'is also the shaft of a rmultiposition housed switch 38, which has an arm 4t) that sweeps a plurality of terminals d2. At its inward end, shaft 32is connected by a Contact spring i4 to a length of conductor 46, such as'copper bar which is molded or otherwise disposed in the lower side d8 of the housing.

' This bar 46 extends the full length ofthe housing and makes an electrical connection through the rear Vside by wire'tl to one output terminal 52 of a step-down transformer 54. This transformer may be connected internally of the television receiver, or it may be connected by a conventional male plug to a regular house outlet of approximately 117 volts. T-he turns ratio of the primary and secondary windings 56 and 5 3 is such that the output e voltage vacross terminals 52 and @ti is approximately 30 volts, orV according to the voltage required for the reversible antenna motor 2u (FGURE 1)'and a second 'reversible lmotor d2 which is utilized in operating the controller itself as below explained.

As indicated, the output' shaft 6d of the reversible motor 62 is coupled by gears 66 and 63 to cause rotation of a threaded shaft or auger 7) which has its opposite "ends disposedgin respective blocks or bearings 72 and 7d,

Ywhich in turn are suitably held stationary in the rear housing side '76 and the front housing side '78. Disposed in threaded engagement with auger itl is an insulative biock 8), made of plastic for example, which may be "caused to move Vleftwardly and rightwardly within the housing 34, according to the direction of rotation of Yreversible motor 62, the operation of ywhich is fully explained below. i

As is apparent in the cross sectional view of FIGURE 4, there are a plurality of longitudinally extending contact bars S2, one for each different one of the television channels 2 through 13, and there is a further and common Contact Vbar 2id. Each of the N station contact bars 82 is embedded Vor otherwise secured in a'respective plastic insulator bar Se, each such insulator bar being spaced from another. In this manner, each insulator 'bar can carry a respective insulative circuit breaker 38 `without interference from any other adjacent such circuit breaker in the longitudinal movement of either along the respectivelength of insulator 86. Each circuit breaker is of hollow rectangular cross section so as to closely surround the respective plastic bar 86 land be movable along the length thereof manually. On the other hand, the vcircuit breaker, which may be made of plastic for example, is securable at a desired lengthwise position along its respective plasticV bar by means of a set screw 9.0.

The central block du, which as previously indicated is ,the contactbars 82 and 34. These spring contacts extend y longitudinally of the contact bars it@ and 84% and ride respectively therealong as the block is moved longitudinally by auger 70. lFurther,` as indicated particularly in FIG- URE 4, all of the springs 92 are electrically interconnected by a copperV or other` type conductor 94.

Spring contacts 92 are disconnected from their .respective station contact bars S2 whenever-block 8G, which slideson guides 96 and 97 in the lower side 4S of they housing, is moved so thatzthe lower portion 93 of a respective circuit breaker S3 comes in-between the spring and'contactY bar. This breaks an electrical circuit which stops the reversible antenna motor 20 and controller 62, asnow explained in more detail.

As will be noted in FIGURE 3 the output terminal all of transformer 54 is connected to the movable arm 161i of a double-pole triple-position UHF antenna control switch 102. This switch is illustrated in its normal position, i.e., in the positionV for automatic operation of the controller during selection of kVHF channels. Therefore, transformer terminal 6d is connected by switch arm 16u yto the common terminal 1M of reversiblemotor 62. The other transformer output terminal 52, as previously ex plained, is connected by line Si) and bar 416 through spring` contact 54 to the selector switch arm di). Each of the stationary switch contacts 42, which correspond to a respective one of the VHF television channels 2 through 13 that can be selected, is electricallyV connected, as shown in FG- -URES 3` and 5, to arespective one of the station contact -bars S2, asvia the external screw 1113 thereof. Therefore, 'the station selected causes current 'from transformer terminal 52 to be directed through the ycorresponding one of the contact bars 82 and thencethrough the respective spring 92 and by the common spring connection 9 4 to the/lower spring 92 andthe common contact'bar S4. in a manner explained in detail below, this contact bar via its upward extensions 166 and 198 causes electrical contact to be made to effect completion of the circuit to reversible' motor 62 at either its forward or reverse terminals 114i and 112. Consequently, motor 62 operates as soon as this circuit is completed. Furthermore, the antenna motor 26B also operatesv at lthis time by virtue of transformer terminal 69 beingconnected also to terminal 114 of a terminal block 116, and motor terminals 11.@ and 112 being connected in parallelv to terminals 118 and 120. The common-lineterminal 114, and the f opposite-direction-voltage terminals v118 and 120 are respectively connectedto motor 20 by lines 122, 124 and 12d, causing the antenna'to rotate while the reversible motors 2d and 62 continue to rotate.

As soon as the disconnector or circuit breaker S8, which is associated with the selected station contact bar S2, is interposed between that contact bar and the respective spring contact 92 by the movement of block 30, the circuit to reversible motors 2@ and 62 is broken and consequently the antenna stops rotating. VAccording to r, this invention, each of the circuit breakers 88 which are -to beused are positioned longitudinally of the respective contact bar at the position which will effect a breaking ofthe circuit to the reversible motors so as to stop lrotation of the antenna atY the approximate position which directs it substantially toward the station selected by'rotation of the selecting knob 22 of FIGURE 1. Since the different stations to be received at any given location will generally be located in different azimuthal directions, the position of disconnectors S8 for those respective stations will be at diiferent longitudinal positions Valong their `respective contact bars 82.

It is a feature of this invention that the overall etfective Ylength of travel of block 8d corresponds to approximately 36.0 of antenna rotation, but nevertheless when reversible motor 52 is energized initially during the change of stations, it may not necessarily first move in the direction by which the contact between the respective contact bar $2 and spring 92 maybe broken by the respective circuit ybreaker 38. Therefore, this invention provides for a 'means to reverse the directionV of rotation of motor' 62,

which at the same tlme reverses the d1rect1on of rotation of the antenna. Of course, when the direction of rotation Vof motor 62 is reversed'the direction of movement of block Sti is also reversed.'VY This reversal is accomplished` vby selectively connecting terminals 111B and 112 of reversible motor'62 to the common contact bar 84;. As previously indicated, this contact bar has at its opposite ends upward extensionsltlo and 1615.V These extensions turn inwardly at their upper end andmake electrical contact respectively with switch arms 123 and 13@ which are snap '5 operated to a leftward or rightward position by virtue of respective springs 132. These springs are secured to a respective collar 134 which surrounds auger 70 and is held in position by a xing arm 136. Switch arms 128 and 130 respectively operate'in squared and inverted U- shaped sections 1?8'and 14th of a longitudinally movable plast-ic rod 142. This'rod has opposite end positions 143 and 144 which extend through respective apertures in the rear and front sides of the housingfor slidable movement therein. .The rod also slidably extends through block 80. 4As'the block moves, say rightwardly in FIGURE 3, its front side will come into physical engagement with the -rearedge of the -U-shapedportion 14@ and will then push -rod 3142 leftward. This will cause switch arms 128 and I130 ftoliip orsnap to their'opposite (rightward) positions whereby the common contact bar 84 becomes disconnected lfromthe terminal 146 which is on the inner end of a metal rod 148 disposed Within the end portion 143 of the plastic rod 142. This metal -rod is connected by line "15h to terminal 1712 :of reversible motor'62. Therefore,

this motor as well as the antenna'motor 20 stops running in its current direction, and due to connection of switch arm 130 to terminal 152, they beginoperating in the opposite direction. As indicated in FIGURE 3, switch terminal 152 is connected 4by a metal rod 154 vwithin the end portion 144 of the plastic rod 4142, and by line 156 and another metal bar 158, which extends the full length of the housing in one of the insulator bars 86, and by line 1151i to the other terminal 1.1i) of reversible motor 62. This causes this motor, as well as the antenna motor, to change direction of operation, and therefore block Si) beg'ins moving leftward in FIGURE 3, and continues to so move until one of its springs is disconnected from an electrically excited Contact bar 82, at which time both motors stop. Then, if stations are again changed, block Sti will resume its leftward travel, and if it is not stopped by 2being -in-tercepted by a proper circuit breaker 88, its

rear edge lwill physically engage the front edge of the V`lU-shaped portion 138 of the plastic rod 142. While motor 62 4then continues to drive block S0 and rod 142 leftwardly, switch arms 128 and 131i will snap back to their opposite positions, ite., back to the positions in which they are illustrated, disconnecting current from switch terminal 152 and connecting it to switch terminal 1.46, whereby the reversible motors both stop and change operational 'direction again. To prevent or reduce arcing or the like :due to yoperation of switch arms 123 and 13u, a condenser 161 is 'preferably connected across lines 151) and 160.

It the antenna rotator motor 29 and control motor 62 get out of r are not initially in synchronization for any `reason, sooner or later they will be resynchronized at Ithe time one or the other of reversing switches 12S and 130 operates, for at one of the switching times motor 20 has then prematurely reached its 360 limit and obviously stalls for a moment until both motors are reversed together.

Since the effective length of travel of block t) from one reversing switch to the other corresponds to approximately 360 of antenna rotation, the relative speed of motor 62, kratio of gears 66 and 68, and pitch and length of auger 70 are obviously so related to the speed and gearing in the conventional antenna rotator 20 to effect the desired full length relationship for a full revolution of the antenna that change of the antenna to any angular position will rat least approximate a corresponding or proportional change in the travel of block Sti.

Instead of block 80 pushing on the U-shaped portions 138 and 14h, the reversing switches may be snapped to their opposite positions by block 80 hitting against a respective extended portion (not shown) of the switch arm-s 12d and 134i which is straight therewith and extends in the opposite direction from the switch armpivot points into the pathway of block Sti. The springs 132 would then be exerting a snapping force on the lower end of such switch arm extensions.

vAnother feature of this invention is 'the inclusion of the UHF lantenna control switch 162 previously mentioned. VIt is the purpose of this switch to allow the operator to control the rotational yposition of the antenna manually rather than automatically controlling same, when the tuner shaft selects the UHF circuits. In FIGURE 5, the switch contacts 42 are numbered 2 through 13, with the twelfth contact being designated by the letter U for self operation. This terminal, in FIGURE 3, is connected by line 162 to the switch arm 164 ofthe UHF control switch 102. Switch arms 10i) and 164 are illustrated in the position in which they are maintained during VHF operation, whereby switch arm 164 completes no circuit but switch arm 1119 provides current to reversible motor 62. However, during UHF operation, it is unnecessary to operate reversible motor 62, though it can be if desired in which case switch 100 would not be necessary and the transformer output terminal 60 would connect directly t0 motor terminal 194 (as well as block terminal 114). Preferably, however, when switch 192 is thrown to either of its other two positions to cause the antenna motor 20 to rota-te the antenna in one direction or another, the input to terminal motor 1114 of reversible motor 62 is broken, thereby energizing only the antenna motor 20 via the transformer output terminal 6G and its connection then only to the appropriate terminal of the antenna motor.

It is to be understood that any number N of contact bars 82 and corresponding spring contacts 92 and circuit breakers S8 may be employed in any given situation according to the requirements thereof regardless of the total number of channels to which the receiving set is tunable. It some of those channels are not useable in a particular locale, of course it is unnecessary to provide equipment in the controller for the unuseable channels, though it might be provided in a universally useable controller.

Thus, it is apparent that this invention has provided for all :of the objects and advantages herein mentioned. Other objects and advantages, and even modifications of this invention, will become apparent to those of ordinary skill in the art upon reading this disclosure, but it is to be appreciated that this disclosure is intended to be illustrative and not limitative, the scope of the invention being defined by the appended claims.

What is claimed is:

1. Apparatus for automatically controlling the rotational position of a receivers antenna, which is rotatable by a reversible rotator, in accordance with which one of N predetermined selectable stations is selected by said receiver, comprising:

N contact bars insulatively extending lengthwise substantially coextensively,

means for selectively energizing said bars automatically in respective correspondence to the said N stations selectable by said receiver,

Icontact means movable in either direction along the length of said N bars for making disconnectable electrical contact therewith,

reversible movin-g means for moving said contact means Ias aforesaid,

reversing means electrically coupled to said contact means and operable when the contact means has reached either of two points separated a given distance corresponding to a predetermined angle of rotation of said antenna for reversing the moving direction of said contact moving means,

N disconnect means lengthwise positionable of said N `bars respectively at predetermined points for the respective N stations for breaking electrical ycontact between said reversing means and any energized one of the said contact bars when the contact means moves adjacent the respective disconnect means,

means coupled to the output of said reversing means vfor reversibly rotating said antenna rotator within the limits of said angle in the corresponding direction and to the corresponding extent as the contact means does until it is disconnected as aforesaid from the energized bar corresponding to a selected station, a receiver adapted rfor both VHF and UHF operation, switch means for manually controlling the direction of said reversible rotator, and means in said selectively energizing means for selectively energizing said switch means only during UHF operation of said receiver, said N contact bars being selectively energizedas aforesaid 4during VHF operation of said receiver. y 2. Apparatus as in claim l including a tuner shaft in said receiver and a shaft in said selectively energizing means, which shafts are integral extensions-of one another or rigidly connected directly together.

3. Apparatus for automatically controlling the rotational position of a receivers antenna, which is rotatable by a reversible rotator, in accordance with which one of N predetermined selectable stations is selected yby said receiver, comprising:

N contact bars insulatively extending lengthwise substantially coextensively,

means for selectively energizing said bars automatically in respective correspondence to the said N stations yselectable by said receiver,

contact means movable in either direction along the length of said N bars respectively for makin-g discon- N disconnect means lengthwise positionable ofrsaid rN a bars respectively at predetermined points for the respective N stations for breaking electrical contact between said reversing means and any energized one of the said contact bars when the contact means moves adjacent the respective disconnect means,

and means coupled to the output of said reversing means for reversibly rotating said antenna rotator within the limits of said angle in the corresponding direction and to the corresponding extent as the con-V tact means does until it is disconnected as aforesaid from the energized bar corresponding to a selected station.

d. Apparatus as in claim 3 wherein said reversing means includes two separate switches commonly coupled to said contact means and disposed at said two spaced points respectively so as to be actuated when said contact Y.

means movesradjacent either ot said points,

said switches being mechanically interconnected so that actuation as aforesaid of either one of the switches automatically causes actuation of the other switch. `5. Apparatus as in claim '3 wherein said contact means com-prises N contact springs electrically interconnected and spaced so as to be in contact respectively with said N contact bars, l

each of said disconnect means being a circuit breaker adjustably secured along the length of a respective conta-ct bar for depressing therefrom the respective one of said contact springs when the contact means moves adjacent that circuit breaker. Y 6. Apparatus as in claim 3 wherein said reversible moving means includes a reversible electric motor,

said contact means comprising a threaded block having a plurality of interconnectedV spring contactors for respectively engaging said contact bars,

said reversible moving means further including a threaded shaft coupled tojsaid electric motor and to the said threads of said block for moving the block and its said spring contactors longitudinally of sai-d contact bars.

y 7j. Apparatus as in claim 6 wherein said reversing means includes two switches each of which has on and off conditions and is coupled to, each of said spring contactors,

said switches being disposed in the path of travel of said block substantially at said two'points for actuation by said block when the-block'travels to the respective one of said two points,

there being means for causing either of said two switches to change to a said condition opposite to that condition-to which the other switch is actuated by said block.

8. Apparatus for controlling the rotational position of a receive'rs antenna rotatable by a reversible electrical motor automatically in accordance with which one of N *predetern'iined selectable stations is selected by the instant angular position of a tuner control of said receiver comt prising:

N contact bars insulatively extending lengthwise substantially coextensively and corresponding respectively to said N stations,

means for coupling one side of a source of electrical energy selectively to any one of said N'bars,

means for connecting said coupling means to said tuner which corresponds to the station then selected bythe tuner control,

a common contact bar, f

contact means connected with said common ,bar and respectively'movable in either direction along the length of said N bars for making disconnectable electrical contact between the said common bar and each of the said N bars, reversible moving means for moving said contact means as aforesaid,

N disconnect means positionable at respective predetermined points along the Vlength of said N bars respectivelyjfor breaking electrical contact between the said common bar and the respective one of the N bars when said contact means moves to the position of the respective one of the N disconnect means,

a pair of reversing switches connected to said common contact bar and disposed at opposite ends of the travel of said contact means,

means, including means Vmovable with said contact means, for actuating both of the said reversing switches to cause reversal of the said moving means and of said contact means at each end of its travel,

and means coupled to the other side of said source and to the output of each of said reversing switches for reversibly rotating said electrical motor and antenna to the rotational position that corresponds to the predetermined longitudinal position of the disconnect means on the Contact bar selectively energized in accorldance with the station selected by the tuner contro 9. Apparatus as in claim 8 wherein the means for actuating both of said reversing switches causes those reversing switches to be actuated to opposite on-ol conditions when the said means that is movable with the contact means actuates either one of the switches at the respective end of its travel.

in. Apparatus as in claim 9 wherein the reversing switch actuating means includes an internally threaded block which carries a plurality of electrically interconnected spring contactors for respectively Vcontacting said N and common contact bars,

said reversible moving means including a reversible electric motor and a threaded shaftcoupled thereto and to the said threads of said block, the output ot said reversing switches being coupled to opposite directional energizing inputs of said electrical motor, Y said kdisconnect means being respective circuit breakers lengthwise adjustable of the respective N bars for control to cause any so energized bar to be the one.

depressing said spring contactors respectively as said block moves adjacent the respective circuit breaker.

11. A system comprising a television receiver,

a rotatable antenna therefor disposed at a remote location,

a first reversible electric motor disposed adjacent said antenna for rotating the antenna in either of opposite directions,

said receiver having a tuner control including a shaft rotatable to any one of a plurality of angular'positions for tuning the receiver to a like number of frequency channels, and

a control mechanism disposed adjacent said tuner control for controlling the said first motor and thereby the rotational position of said antenna automatically in accordance with which of the stations is selected by said tuner control shaft;

said mechanism comprising a contact bar selector having an arm mechanically coupled to rotate with said tuner control shaft,

a plurality of first contact bars insulatively extending lengthwise substantially coextensively and corresponding respectively to the channels selectable by said tuner control,

means for coupling one side of a source of electrical energy to said selector arm for selectively energizing said rst contact bars,

a block having a predetermined peripheral configuration 'and having an axially ext-ending threaded aperture,

a second reversible electricl motor a threaded shaft engaging the threaded aperture of said block and being coupled to the output of said motor for causing said block to move longitudinally of said threaded shaft in either direction according to the direction of rotation of said second electrical motor,

a plurality of rst spring contactors electrically interconnected and disposed about the periphery of said block,

said contact bars being also disposed about the periphery of said block so that said spring contactors respectively engage the contact bars during movement of the block along the path of said threaded shaft,

a further contact bar,

a further contactor on said block electrically connected with each of the aforesaid spring contactors for making continuous engagement with said further contact bar,

a pair of electrical switches each having respective on and off conditions effected by a movable arm,

said arms being commonly coupled to said further contact bar and said switches being disposed at opposite ends ofthe travel of said block so as to be actuatable thereby,

means mechanically coupling the output contacts of said switches together to cause either switch to change to its opposite condition upon the other being actuated from that condition by said block, and

means for electrically coupling :the output contacts of said switches to both of the aforesaid motors to cause same to rotate in corresponding angular directions simultaneously and to be reversed or stopped at the same time, actuation of said switches by said block being eiiective to reverse the direction of rotation of said motors, and the respective circuit breaker on the energized one of the first contact bars corresponding to the channel selected by the tuner control effecting a stop of the motors by breaking engagement between that contact bar and the associated spring contactor.

References Cited bythe Examiner UNITED STATES PATENTS ORIS L. RADER, Primary Examiner. 

1. APPARATUS FOR AUTOMATICALLY CONTROLLING THE ROTATIONAL POSITION OF A RECEIVER''S ANTENNA, WHICH IS ROTATABLE BY A REVERSIBLE ROTATOR, IN ACCORDANCE WITH WHICH ONE OF N PERDETERMINED SELECTABLE STATIONS IS SELECTED BY SAID RECEIVER, COMPRISING: N CONTACT BARS INSULATIVELY EXTENDING LENGTHWISE SUBSTANTIALLY COEXTENSIVELY MEANS FOR SELECTIVELY ENERGIZING SAID BARS AUTOMATICALLY IN RESPECTIVE CORRESPONDENT TO THE SAID N STATIONS SELECTABLE BY SAID RECEIVER CONTACT MEANS MOVABLE IN EITHER DIRECTION ALONG THE LENGTH OF SAID N BARD FOR MAKING DISCONNECTABLE ELECTRICAL CONTACT THEREWITH, REVERSING MOVING MEANS FOR MOVING SAID CONTACT MEANS AS AFORESAID, REVERSING MEANS ELECTRICALLY COUPLED TO SAID CONTACT MEANS AND OPERABLE WHEN THE CONTACT MEANS HAS REACHED EITHER OF TWO POINTS SEPARATED A GIVEN DISTANCE CORRESPONDING TO A PREDETERMINED ANGLE OF ROTATION OF SAID ANTENNA FOR REVERSING THE MOVING DIRECTION OF SAID CONTACT MOVING MEANS, N DISCONNECT MEANS LENGTHWISE POSITIONABLE OF SAID N BARS RESPECTIVELY AT PREDETERMINED POINTS FOR THE RESPECTIVE N STATIONS FOR BREAKING ELECTRICAL CONTECT BETWEEN SAID REVERSING MEANS AND ANY ENERGIZED ONE OF THE SAID CONTACT BARS WHEN THE CONTACT MEANS MOVES ADJACENT THE RESPECTIVE DISCONNECT MEANS, MEANS COUPLED TO THE OUTPUT OF SAID REVERSING MEANS FOR REVERSIBLY ROTATING SAID ANTENNA ROTATOR WITHIN THE LIMITS OF SAID ANGLE IN THE CORRESPONDING DIRECTION AND TO THE CORRESPONDING EXTENT AS THE CONTACT MEANS DOES UNTIL IT IS DISCONNECTED AS AFORESAID FROM THE ENERGIZED BAR CORRESPONDING TO A SELECTED STATION, A RECEIVER ADAPTED FOR BOTH VHF AND UHF OPERATION, SWITCH MEANS FOR MANUALLY CONTROLLING THE DIRECTION OF SAID REVERSIBLE ROTATOR, AND MEANS IN SAID SELECTIVELY ENERGIZING MEANS FOR SELECTIVELY ENERGIZING SAID SWITCH MEANS ONLY DURING UHF OPERATION OF SAID RECEIVER, SAID N CONTACT BARS BEING SELECTIVELY ENERGIZED AS AFORESAID DURING VHF OPERATION OF SAID RECEIVER. 